Abstract: Disclosed is a fluororesin-coated polymer film for reinforcing a polymer electrolyte membrane, wherein the fluororesin-coated polymer film is fabricated by forming on at least one side of a polymer film a coating of a reaction product of (A) a fluorine-containing copolymer composed of a fluoroolefin, a cyclohexyl group-containing acrylic ester, and a hydroxyl group-containing vinyl ether, and (B) a crosslinking agent having two or more isocyanate groups. The polymer film according to the present invention not only exhibits sufficiently high initial adhesion strength, with respect to the polymer electrolyte membrane, but also retains thereafter high adhesion strength in actual operating environments.

Abstract: An elastic composite film provided with a sintered ePTFE film and an elastomeric resin layer, produced by continuously forming the elastomeric resin layer on at least one side of the sintered ePTFE film, continuously elongating the resulting multilayer film at less than the yield point of the expanded, sintered, porous film and at an elongation factor of 1.3 times or more in the biaxial directions, or in the uniaxial direction without contracting in the direction perpendicular to the direction of elongation, and relaxing the resulting elongated multilayer film, wherein when the composite film is elongated by 10% in the longitudinal and/or transverse direction, the tensile stress of the composite film is 2.5 N/15 mm or less, and/or the elongation percentage of the composite film in the longitudinal and/or transverse direction is 30% or more and the elongation recovery rate is 70% or more.